Ethics of germline genome editing to prevent genetic diseases from an Islamic perspective
[ Ссылка ]
Germline genome editing to prevent genetic diseases still elicits some degree of controversy among Islamic scholars. To resolve conflicting opinions, it is best to critically examine whether this is aligned with Islamic principles based on Qawaid Fiqhiyyah (Islamic legal maxims) that incorporates Qaṣd (intention), Yaqin (certainty), Ḍarar (injury), Ḍarurah (necessity), and Urf (local customs).
The first legal maxim related to Qaṣd (intention), refers to evaluating new medical technologies based on the intended objectives of its applications.
In this case, the key objective is to enable Muslims, who are carriers or affected with a genetic disease, to have healthy blood-related offspring of their own, rather than opting for Muslim-style adoption (Kafala). Resorting to gamete donation is explicitly prohibited by the Sunni branch of Islam, as this is considered akin to adultery (Zina). This would thus align with one of the five key objectives of sharia law (Maqasid al-Shariah), namely the protection of lineage or progeny (Hifz al-Nasl).
The second legal maxim related to Yaqin (certainty) within the context of Islamic bioethics, refers to the current state of scientific knowledge and effectiveness of new medical techniques, and whether there are any safer or better alternative treatment options.
In this case, there is a much safer and less complex alternative technique – preimplantation genetic testing (PGT) of human embryos, a mature technology platform with proven effectiveness in screening various known genetic defects in IVF embryos, without any risks of permanent genetic modifications being transmitted to future generations. Nevertheless, there may be some cases whereby genome editing could be preferable to PGT. For example, rare instances whereby both parents are affected with the same genetic disease, particularly those involving dominant rather than recessive gene mutations, such as neurofibromatosis. Yet another alternative would be to carry out gene therapy on the fetus in utero. Upon prenatal diagnosis of a genetic disease, cells can be extracted from the fetus with minimally-invasive surgical techniques, subjected to genome editing, and re-transplanted back to the fetus. This is technically easier to achieve because thousands of cells are readily-available from the fetus, unlike the very few cells of an embryo.
The third legal maxim related to Ḍarar (harm) questions the risks of potential harms associated with new medical techniques. Genome editing using the CRISPR/Cas9 approach is neither completely error-free nor without risks.
These include unintended on-target and off-target errors, and mosaicism, whereby only some but not all cells within the embryo have the correctly-edited genes. The relatively small numbers of embryos typically produced by each couple during IVF treatment would thus impose severe limitations in screening out such gene-editing errors due to the extremely small sample size. By contrast, millions of non-reproductive (somatic) cells are readily available for genome editing and subsequent screening of gene-editing errors. More recently, cells in early human embryos have been shown to be unable to repair the DNA breaks made during CRISPR/Cas9 genome editing process (see BioNews 1196).
The fourth legal maxim related to Ḍarurah (necessity), questions the necessity and/or urgency of using new medical techniques.
Because germline genome editing of human IVF embryos is not life-saving in itself but intended to save the life or health of a yet unborn future offspring, there is much less necessity and urgency as compared to curing patients who are affected by serious genetic diseases. Hence, it should be ranked lower in priority for public healthcare spending and Government-funded research, based on the Islamic concept of Fiqh al-Awlawiyyat (understanding of priorities).
The fifth legal maxim related to Urf (local customs), refers to taking into account local customs and traditions (if they are compatible with Shariah), when deciding on any new issues, such as novel medical techniques.
In this case, the devastating impact of serious genetic diseases on patients and their families is well-known. Hence there is almost universal public support worldwide for developing new medical techniques to prevent genetic diseases.
The pertinent question is whether germline genome editing is the best solution?
